BUILD: Update EXTRA_DIST

[ci skip]
BUILD: Set dist_doc_DATA

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BUILD: Specify project email address and website in AC_INIT

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BUILD: Comment in Makefile.am is #, not dnl

[ci skip]
DOCS: Rename README.eos in Lua to README.xoreos

[ci skip]
BUILD: Add more files to EXTRA_DIST

[ci skip]
COMMON: Decrease malloc calls in UString::toLower()/toUpper()

Reserve the usual size of the lowered/uppered string.
DOCS: Add a little README section about compiling xoreos

Linking to our wiki page regarding compiling xoreos.

[ci skip]
DOCS: Syntax-highlight config example in README.md

[ci skip]
AURORA: Add GUI level hooks for mouse state change.
KOTOR: Mouse image now changes on click.
AURORA: Add isEmpty() to 2DA cell
Though an empty cell returns a default value, it might happen that this
value can be the same as a non-empty cell and hence there is no way to
check emptiness.
NWN: Add setter/getter to creature's portrait

Also add an initial value to creature's portrait.
GRAPHICS: Allow to change textures node in-game
NWN: Add access to nodes in ModelWidget
NWN: Nitpicky style fixes
AURORA: isEmpty() -> empty()

For consistency's sake.

See also 9b35a591a3a1c381866db12dcf1cc4fe70ae211a
NWN: Fix colour change when enabling button

When buttons were first disabled and then enabled again, the colour
remained grey. They will now change accordingly.
NWN: Handle mouse state events in Portrait
NWN: Add SetBorderColor() to Portrait